Mirror command flips normals incorrectly(?)

I made a right part of this door and used MirrorAll 0,0,1 on an identical object to make a left side, but somehow it has flipped normals both in Z and X directions. You can see that on the mirrored half of the door - it's darker while both halves use the same texture. This doesn't happen when I mirror along other axis (for example, use a MirrorAll 1,0,0 and RotateAll 0,1,0,180 combo)

Thanks, now that's an old bug...

Typo, which as as far as I can find seems to date back to Michelle's builds

Lol Openbve is full of these old bits and bugs. I once went to find all sound problems - ended up with a huge list I've posted in a separate topic some time ago. Might be not a priority, but that's a lot of stuff with the sound system alone